Skin lesions in humans bitten by European pigeon tick Argas reflexus (Fab.) (Ixodida: Argasidae) massively occurring in the Upper Silesian conurbation of south-west Poland.

INTRODUCTION AND OBJECTIVE: The great number of pigeon populations in many European cities promotes the spread of the European pigeon tick (Argas reflexus), the bites of which cause local and systemic reactions. The aim was to study the occurrence of A. reflexus in several cities of Upper Silesia, and skin lesions caused by A. reflexus tick bites in humans. MATERIAL AND METHODS: The results of investigations carried out in 1995-2002 in five cities located in the Upper Silesian conurbation are presented. Specimens of A. reflexus were collected for one hour in attics and lofts inhabited by these ticks. A history of skin lesions caused by bites was taken from residents who had been infested by A. reflexus. The development of skin lesions was monitored for three months in two individuals who had been bitten several times by these arthropods. RESULTS: In the localities, 987 A. reflexus specimens were collected, including 334 females, 269 males, and 384 various nymphal stages. Within one hour, 38-109 ticks specimens were collected at the study sites. Cases of attacks by unengorged A. reflexus were reported in all the habitats located in the residential buildings; the ticks were also found in residents' flats and in staircases. Residents who had been repeatedly attacked by European pigeon ticks developed a strong inflammatory reaction to the components of tick saliva, and had purple papules with necrosis in the centre of the lesion. The tick bite areas exhibited scars and hyperpigmentation. CONCLUSIONS: Individuals attacked by A. reflexus several times are at risk of development of severe persistent local reactions to bites. Pigeon ticks, trophically associated with pigeons present abundantly in the Upper Silesian conurbation and other European urban habitats, pose a serious threat to public health.

Pigeon tick bite: A neglected cause of idiopathic nocturnal anaphylaxis.

Anaphylaxis is a serious systemic allergic reaction with rapid onset and potentially life-threatening. We report in detail a case of severe nocturnal anaphylaxis due to pigeon tick bite showing the diagnostic value of the extract and the recombinant allergen in the diagnostic procedures (basophil activation test, IgE immunoblot, and experimental ImmunoCAP). Apart from the presented case, we describe that during the last 10 years, we have collected 28 cases of allergy to Argas reflexus from several European countries. We suspect that this allergy is underdiagnosed because of the lack of diagnostic reagents. Because of the growing number of pigeons in Middle and Southern Europe cities, some cases of idiopathic anaphylaxis could potentially be caused by A. reflexus in those countries. The identification of pigeon ticks as a trigger of anaphylaxis would greatly improve medical care and advice for these patients as the parasite can be exterminated by eradication measures to avoid further incidents.

Biocontrol of pigeon tick Argas reflexus (Acari: Argasidae) by entomopathogenic fungus Metarhizium Anisopliae (Ascomycota: Hypocreales)

The pigeon tick Argas reflexus is a pathogen-transmitting soft tick that typically feeds on pigeons, but can also attack humans causing local and systemic reactions. Chemical control is made difficult due to environmental contamination and resistance development. As a result, there is much interest in increasing the role of other strategies like biological control. In this study, the efficacy of three strains (V245, 685 and 715C) of entomopathogenic fungus Metarhizium anisopliae for biological control of three life stages of pigeon tick A. reflexus including eggs, larvae, engorged and unfed adults was investigated under laboratory conditions. Five concentrations of different strains of M. anisopliae ranging from 10³ to 10(7) conidia/ml were used. All fungal strains significantly decreased hatchability of A. reflexus eggs. Strain V245 was the most effective strain on the mortality of larval stage with nearly 100 percent mortality at the lowest concentration (10³ conidia/ml) at 10 days post-inoculation. The mortality rate of both engorged and unfed adult ticks were also increased significantly exposed to different conidial concentrations compared to the control groups (P < 0.05) making this fungus a potential biological control agent of pigeon tick reducing the use of chemical acaricides.

Biocontrol of pigeon tick Argas reflexus (Acari: Argasidae) by entomopathogenic fungus Metarhizium Anisopliae (Ascomycota: Hypocreales).

The pigeon tick Argas reflexus is a pathogen-transmitting soft tick that typically feeds on pigeons, but can also attack humans causing local and systemic reactions. Chemical control is made difficult due to environmental contamination and resistance development. As a result, there is much interest in increasing the role of other strategies like biological control. In this study, the efficacy of three strains (V245, 685 and 715C) of entomopathogenic fungus Metarhizium anisopliae for biological control of three life stages of pigeon tick A. reflexus including eggs, larvae, engorged and unfed adults was investigated under laboratory conditions. Five concentrations of different strains of M. anisopliae ranging from 10(3) to 10(7) conidia/ml were used. All fungal strains significantly decreased hatchability of A. reflexus eggs. Strain V245 was the most effective strain on the mortality of larval stage with nearly 100% mortality at the lowest concentration (10(3) conidia/ml) at 10 days post-inoculation. The mortality rate of both engorged and unfed adult ticks were also increased significantly exposed to different conidial concentrations compared to the control groups (P < 0.05) making this fungus a potential biological control agent of pigeon tick reducing the use of chemical acaricides.